Intravenous iron as adjuvant therapy: a two-edged sword?

The importance of iron in the manufacture of erythrocytes is self-evident. In recent years, the treatment of anaemia of end-stage renal disease with recombinant human erythropoietin (epoetin) has been optimized by adequate iron supply. Intravenous therapy with dextran-free iron compounds has become the ideal and necessary companion of epoetin therapy. Anxiety has been expressed by clinicians and researchers over the impact of excess levels of iron following i.v. administration. Their concerns have included the potential for short-term side effects such as anaphylactic reactions and response to 'free iron'. Long-term concerns have included the possibility of increased infection, oxidative stress and cardiovascular disease with higher levels of iron. The literature also implies that i.v. iron could be a 'two-edged sword', i.e. on the one hand, it optimizes epoetin therapy, while on the other, it puts the patient at greater risk of other complications. This review assesses the evidence for these concerns and concludes that i.v. therapy with dextran-free iron compounds, such as iron sucrose, optimizes epoetin therapy with no direct evidence of any short-term or long-term complications.